The tropical border river between Guatemala and Mexico is the most important river in Mesoamerica. Its basin, which covers an area of 106,000 km², carries 59 billion cubic meters of water annually to the Gulf of Mexico.

Together with Tikal, Copán, Piedras Negras and Palenque, Yaxchilán was one of the most important Mayan cities of the classical period, both in terms of the size of the complex and the number and aesthetic quality of its buildings and monuments. The well preserved stone lintels with their detailed depictions of central Mayan rituals are particularly famous. Yaxchilán’s other peculiarities are the high level to which women were involved in ceremonies, the complex cosmological symbolism of his stelae, and finally the detailed documentation of the reign of two Late Classical rulers: the shield Jaguar (Itzamnah Balam) and his son Jaguar IV (Yaxun Balam). Only during their reign (726-770 AD) Yaxchilán laid down his vassal status and became the dominant power at the Usumacinta.

Father and son were also responsible for the expansion of the city to its present size. This expansion followed the course of the sun over the earth on an architectural and planning level. Two imaginary intersecting axes cut through the centre from southeast to northwest and from northeast to southwest respectively and indicate the course of the sun at sunrise at the summer and winter solstice. From the more than 100 preserved and deciphered hieroglyphic texts, including a hieroglyphic staircase, the history of the city between 359 and 808 AD has been reconstructed. During the 8th century Yaxchilán thus also dominated the neighbouring Bonampak.